Process for distilling mineral oil



A. E. PEW, JR., ET AL PROCESS FOR DIST-ILLING MINERAL OIL Filed Feb.-23, '1924 2 sheets-shewv 1 May 8, 1928.

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A. E. PEW, JR., ET AL PROCESS FOR DISTILLING MINERAL OIL May s, 192s,

Filed Feb. 23. 1924 2 Sheets-Sheet2 4Patented May 8, 1928.

' UNITED STATES 1,668,602l PATENT OFFICE.

ARTHUR E. PEW, JE., or EEYN MAWE, AND HENRY rHoMAs, or EIDLEY PAEH,PENN- sYLvANrA, AssIGNoEs rro SUN 011. COMPANY, or PHILADELPHIA,PENNSYL- vANrA, A CORPORATION or NEW JERSEY.

PROCESS FOR DISTILLING MINERAL OIL.

Application led February 23, 19,24. Serial No. 694,474.

The object of our invention is to provide a process for the fractionaldistillation of crude oil into gasoline fractions of various gravities,turpentine substitutes and kero- 5 sene. The invention is applicable tothe distillation of oil into other fractions of progressively increasingboiling points, and it will be understood that in specifying theabove-named lighter constituents of .crude 1o oil, we do not mean to beconfined thereto but intend to include any other fractions of differentboiling points recoverable by distillation from crude oil, ordistillatestherefrom, or residues from such distillation. ,In the drawings, whichshow .a preferred apparatus for carrying out the process- Fig. 1 is adiagram of the plant. Fig. 2A is a diagram of a form of tower adapted tooperate as a vaporizing fractionator. f

Figs.f3 and gare respectively sections on the lines 3-3 and 4 4 of Fig.2.

In the drawings we have shown five towers and three stills, although thenumber of towl 26 ers and stills may be yvaried dependent upon obtain. f

Through line a crude oil is pumped from a source of supply (optionallythrough a heat 30 exchanger b) into a vaporizing fractionator c. Vaporsfreed herein from oil which are very light, ass to condenserd. esidualoil 1s pumpe through reflux con ensers z', j and k on towers g andh'respectively, and through heat exc anger m to the vaporizerfractionator tower n. Vapors from tewer n go' to condenser o. Residualoil from tower n flows into the vaporizer pans or evaporator pans 40 pin still r. Vapors from still 'r pass into fractionating tower f. Vaporsnot condensed in tower f go to condenser d, while reiuxed condensategoes to one of the stills, preferably returning to still 1'. Residualoil from still 1' goes to still s. Vapors fromvst-ill .s

pass into the fractioning tower g, vapors uncondensed therein passing tocondenser u and reluxed condensate going to one of the stills, preferablreturning to still s. Residual oil from sti s flows into still t.,Vapors from still t pass into fraction'ating tower` h, vapors notcondensed therein passing to c ondenser 'v and reuxed condensatereturnin to still t. Residual oil from still t is pumpe the numberof'distillates that it is desired to through line e successively.

through line w and heat exchangers m and b.' One of the objects of theinvention is to obtain -rubber gas, which is a light gasoline from whichthe very lightest fraction has been removed and which contains no heavygasoline fractions. Another object of the invention is to sepa-rategasoline suitable for motor propulsion, which gasoline may be obtainedby mixing said very lightest fraction with the heavier fraction thatmust be excluded from rubber gas. The arrangementabove described and theprocess carried out therein are well'adapted to effect these purposes. I

lhe cold crude oil flowing through pipe a enters the vaporizerfractionator c heated to a relatively low temperature, or alternatively,not heated at all. It is not intended to vaporize in tower c more thanabout one per cent of the oil. In passing through reflux condenser z', jand lc and through heat ex- 75 changer m, the temperature of the oil isSubstantially raised, although not to the temperature in still 'l'.Hence, in tower n, more or less light gasoline will be evaporated andpass to condenser o. With certain crude oils, the proportion of gasolinesuitable for rubber gas is something over eleven per cent of theoriginal crude oil, and the tempera-` ture of the oil entering tower nmay be regulated, particularly by controlling 'the exchange of heat inexchanger m, so as to insure the vaporization in Atower 'n of thispercentage. The fractionating evaporizing tower c is preferably of thetype shown in Fig. 2 and comprises circular flanged plates 10 of smallerdiameter than the inner diameter of the tower c alternating with annularianged plates 11 of a diameter nearly or quite equal to the innerdiameter of the 95 tower c. Thereby a staggered course is provided forthe vapor, which flows through the central orifices in the plates 11 andpast the peripheral edges of the plates l0. The exit end of pipe aenters the tower at about its 106" center so that the lower part of thetower acts as a vaporizer and the upper part of the tower as afructionator. Each plate is provided with an annular group of smallholes 12, through which the oil escapes from plate to plate. Thevaporizing fractionating tower n preferably comprises three sections: alower pans p within the still.

section 20, a mediate section 2l and an upper section 22. The lowersection 20 may comprise plates similar to plates 10 and 11 in tower c.The mediate section 21 may consist of a tier of fine screens. The uppersection 22 preferably comprises a tier of plates, etc., so constructedas to insure the bubbling of the vapors through the oil 1n the passageof the vapors upwardly through the plates. Known constructions aresuitable for the purpose. A tower well adapted the purpose is shown inFig. 1l of an apphcation filed by us (Case 1) of even date herewith,Serial No. 694,470.

Residual oil from tower n flows, as above stated, into the still r. Itis preferred not to introduce this oil directly into the body of the oilin the still, but to flow it onto These pans comprise a wide upper panand two narrower lower pans, both slightly inclined to the horizontal inopposite directions and extending, preferably, the length of the still.The oil flows along the upper pan and the lower pans successively, thelighter fractions of entering oil being vapor-ized thereon, suchvaporization being facilitated by the spreading out of the oil over anextended surface in a thin film, by the intimate contact of thisextensive film of oil with hot` vapors, and by the heat of the pansthemselves. By suitably regulating the still temperature, all of thegasoline in the oil will pass, together with some heavier fractions,into the tower f.

The tower f may have an entirely open interior filled with pieces ofclay or other refractory material 30, such as the well known Reschigrings. Vapor escaping through the reflux condenser i and passing to thecondenser l may comprise a little over nine per cent of the originalcrude oil. In this condenser it mixes with the very lightest one percent of the oil coming from tower `c, the resultant gasoline being welladapted for -motor propulsion. 0f course, if desired, thetwo`\distillates may be separately condensed before mixing.

The condensate from tower f flows back into one of the stills,preferably still r. Residual oil from still 77 goes to still s, flowing(preferably) directly onto pans p therein similar to pans p in still 7and functioning in the same way. Vapors from still s pass into thefractionating tower g, the internal construction of which may be thesame as the upper section 22 of tower n. By suitably regulating thetemperatures of st1ll s and reflux condenser j, the oil condensed fromthe vapor escaping from the tower will be a suitable turpentinesubstitute. if an appropriate crude oil, such as Texas oil, is used, andmay comprise (say) nearly eleven per cent of the crude oil.

If it is desired to still furtherv fractionate the oil, the condensatefrom tower g may be returned to one of the stills, preferably still s,andthe residual oil from still s conveyed to still t, flowing,preferably, directly onto pans p therein similar to pans p in stlll fr.Vapors from still t pass into the fractionating tower It, whose internalconstruction may be thel same as that of tower g.l By suitablyregulating the temperatures of still t and reflux condenser lc, oilcondensed from the vapor escaping from the tower may be kerosene of anydesired gravity, comprising (say) over thirteen per cent of the crudeoil.

'lhe condensate from tower lL may go back to still t and the highlyheated residual oil from this still may be utilized to substantiallyraise the temperature of the oil flowing through line e to the tower n.Thence the residual oil may go to storage; or it may be subjected tofurther distillation. In fact,

it may be further distilled in an apparatus embodying this invention,which, as hereinbefore stated, is adapted'for the fractionaldistillation of oil from which thelighter fractions have been separatedby any process or 1n any apparatus.

Having now fully described our invention, what we claim and desire toprotect by Letters Patent is:

l. 'lhe process of fractionally distilling 95 the unvaporized oil andsubjecting ittoheat,

vaporizing part of the heated oil and fractionatinrr the vapors at asecond locus, conveying flic residual oil and condensate from the locusof said vaporization and fractionation to a body of oil at a thirdlocus, heating said Ibody of oil to effect its partial vaporization,distributing the oil during its flow to said body of oil over anextended surface and in contact with the vapors from said body of oil,thereby partially vaporizing the oil in the course of its flow to saidbody of oil, fractionating and condensing at a fourth locus the vaporsfrom the last named flowing oil and from the body of oil, and subjectingthe residual oil from said body of oil and the condensate from the lastnamed fractionation to further treatment adapted to effect their partialvaporization and condensation.

2. The process of fractionally distilling, 129

oil to produce a light gasoline and a heavier hydrocarbon suflicientlylight for use as m05- tor fuel, which comprises establishing a flow ofrelativelycold oil and durin its iiow sof diffusing it at one locus asto e ect evaporation of a very small' fraction of the oil, flowing awaythe unvaporized oil and subjecting it to heat, flowing away the heatedoil and so diffusing it at a second locusl as to effect its partialvaporization and fractionating 13 l the vapors and condensing them torovide a light gasoline, conveying the resi ual oil and condensate fromthe locus of said vaporization and fractionation to a body of oil at athird locus heating said body of oil to effect its partial vaporization,fractionating at a fourth locus the vapors from said body of oil, andcondensing the vapors of the first specified, evapora-tion andfractionation and the vapors of the last specified fractionation andmaking' therefrom a mixed distillate adapted for motor. propulsion.

The process i of fractionally distilling oil which comprisesestablishing a flow of relatively coil oil and during its flow sodiffusing it at one locus as to effect evaporation of a small fractionof the oil, flowing away the unvaporized oil and subjecting it to heat,vaporizing part of the heated oil and fractiona-ting the vapors at asecond locus, heating a body of oil at a third locus to effect itspartial Vaporization, fractionating at a fourth locus the vapors fromsaid body of oil, and conveying to said body of oil the residual oil andcondensate from the second and fourth loci and in the course of theiriow distributing them over an extended suriace and in contact with thevapors from said body of oil,lthereby effecting their partialvaporization in the course of their ow 'oil which comprises heating oiland flowing away the heated oil and so diffusing it at one locus as toelfect its partial vaporization and fractionating the vapors, heating abody of oil at a second locus to effect its partial vaporization,fractionating the vapors from said body of oil ata third locuszconveying the residual oil and condensed 011 from the locus of the'h'rst evaporation and fractionation and also`the condensed oil from thelast'fractionation to said body of oil andin the iow of such oildistributing it over an extended surface and in contact with the vaporsfrom said body of oil, thereby partially vaporizing such oil `in thecourse of its fiow to said body of oil and mixing the vapors from suchflowing oil with the vapors from the body of oil.

In testimony of which invention, we have hereunto set our hands, atPhiladelphia, Pa., on this 14th day of February, 1924.

ARTHUR E. PEW, JR. HENRY THOMAS.

